Copper vs. Aluminum Wiring: Which to Use?

A group of exposed copper wiring.

Perhaps you have some questions about whether aluminum wiring is suitable for your home. Usage of this wiring for residential purposes was extensive from about the mid-1960s. However, from the late 1970s, its popularity waned until it picked up again in the 1990s. Regardless of its high cost, copper continues to be used more widely than aluminum for home wiring, but each material has its advantages and disadvantages.

Advantages of Aluminum Wiring

Due to its lightweight nature, aluminum is fairly malleable and easy to work with. The lightweight nature of aluminum is beneficial when wiring is to be done over long distances as it makes the job less rigorous. Aluminum also reduces corona, an electric discharge associated with high power transmissions.

When it comes to cost, aluminum is more affordable than copper wire. With aluminum, you will require about half the amount you would need if the copper wire were used instead. When extensive wiring needs to be done in your home, the difference between the two materials can give you significant savings.

Disadvantages

If not installed properly, aluminum wiring can raise the risk of house fires. When aluminum wire warms, it expands and when it cools, it contracts. The tightness of the wiring decreases with each progressive warm-cool cycle experienced, creating the phenomenon known as “cold creep." These loose connections can cause sparking which may result in fires. Wires progressively heat up and could even melt surrounding insulation and fixtures, triggering a fire.

Aluminum wires require higher maintenance than copper wiring. This is partly due to the high wear and tear rate as well as a greater risk of fire. For example, aluminum also undergoes corrosion when it encounters certain metal compounds, and this oxidization gives the connection increased resistance. This also adds to overall home maintenance costs.

Advantages of Copper Wiring

Copper has one of the highest electrical conductivity rates among metals, which allows it to be soldered with ease. It also makes it possible for smaller conductors to be used to transmit power loads. Smaller conductors are easier to transport and install, and they cost less, which helps manage wiring costs. Copper doesn’t undergo the same extreme expansion and contraction cycles as aluminum so it is a more stable material to use.

Due to its high ductile properties, copper can be formed into very fine wire, making it more versatile. Copper has high tensile strength as well, so it can undergo extreme stress but show minimal signs of wear and tear. This makes the wiring more durable than aluminum. Due to its great resilience, high durability, low maintenance, and high performance, copper wiring also add to home value.

Disadvantages

Copper wire costs much more than aluminum, so when extensive wiring is necessary, the overall costs may prove to be prohibitive. Copper is also heavier which can add to the difficulty in the wiring. More supports are required to secure the heavier wire in place, which also adds to the overall cost.